module ActiveSupport::LoggerThreadSafeLevel

def add(severity, message = nil, progname = nil, &block) # :nodoc:

:nodoc:
FIXME: Remove when the minimum Ruby version supports overriding Logger#level.
Redefined to check severity against #level, and thus the thread-local level, rather than +@level+. 
def add(severity, message = nil, progname = nil, &block) # :nodoc:
  severity ||= UNKNOWN
  progname ||= @progname
  return true if @logdev.nil? || severity < level
  if message.nil?
    if block_given?
      message  = yield
    else
      message  = progname
      progname = @progname
    end
  end
  @logdev.write \
    format_message(format_severity(severity), Time.now, progname, message)
end